#include"stdio.h"
main()
{
	int i,m;
	printf("Enter a number:");
	scanf("%d",&m);
	for(i=2;i<=m/2;i++)
		if(m%i==0)
			break;
		if(i>m/2&&m!=1)
			printf("%d is a prime number!\n",m);
		else
			printf("No!\n");
		return 0;
}
